This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A165637 #16 Sep 08 2022 08:45:48 %S A165637 2,17,43,53,59,61,71,83,89,107,113,127,131,137,139,149,163,167,173, %T A165637 179,181,191,193,199,223,229,241,251,269,271,277,281,283,311,313,317, %U A165637 347,373,379,383,401,419,421,431,433,439,457,461,467,479,499,503,523,541,557,563 %N A165637 Primes p such that (p^2-3)/2 is not a prime number. %H A165637 Vincenzo Librandi, <a href="/A165637/b165637.txt">Table of n, a(n) for n = 1..1000</a> %F A165637 A000040 \ A110589. - _R. J. Mathar_, Sep 26 2009 %e A165637 For p=17=a(2), (17^2-3)/2=143 is not a prime. For p=43=a(3), (43^2-3)/2=923 is not a prime. %t A165637 Select[Prime[Range[200]], !PrimeQ[(#^2 - 3) / 2]&] (* _Harvey P. Dale_, Dec 09 2011 *) %o A165637 (Magma) [p: p in PrimesUpTo(600)| not IsPrime((p^2-3) div 2)]; // _Vincenzo Librandi_, Sep 12 2013 %K A165637 nonn,easy %O A165637 1,1 %A A165637 _Vincenzo Librandi_, Sep 23 2009 %E A165637 Extended by _R. J. Mathar_, Sep 26 2009